Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2001-06-07
2004-01-20
Hayes, Michael J. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S110000
Reexamination Certificate
active
06679864
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the invention relates to shield systems for protecting against needle sticks, and syringes including such systems.
2. Brief Description of the Related Art
Syringes are well known medical devices for administering medicaments, drugs and vaccines to patients. Prefilled syringes are generally considered as those which are filled with a selected dosage of medicament, drug or vaccine by a pharmaceutical manufacturer for distribution to the end user. They are generally comprised of a glass barrel which contains the medicament, drug or vaccine, and a stopper slidably mounted within the barrel. The distal end of the barrel includes a needle cannula or the like affixed thereto or a connector for a needle cannula assembly such as a Luer fitting. The proximal end of the syringe includes an integral flange and is open to allow the insertion of a stopper of a plunger assembly. The plunger and stopper assembly allows the user to apply manual force to the plunger, causing the medicament, drug or vaccine to be delivered through the needle cannula or other piercing element. The healthcare worker or patient grips the flange and applies pressure to the plunger generally with the thumb.
The use of a sharp-pointed piercing element entails the risk of an accidental needle stick. To avoid such accidents, many prior art hypodermic syringes have included rigid cylindrical safety shields telescoped over the syringe barrel. These shields can be moved between a retracted position, where the needle is exposed for use, to an extended position where the needle is surrounded by the shield. U.S. Pat. Nos. 4,425,120, 4,573,976, 4,850,994 and 4,923,447 disclose various shield systems for hypodermic syringes. The latter two patents disclose shields which may be spring-actuated. It is ordinarily desirable to lock the needle shields in the protected positions, and a number of prior art designs provide for such locking. Some systems, such as those disclosed in U. S. Pat. Nos. 5,201,708, 5,242,240 and 5,318,538 are designed to allow the shields to be retracted from their locked, extended positions.
A shield system for protecting the piercing element of a prefilled syringe is also disclosed in European Publication No. EP 0 740 942 A1. The disclosed system includes a holder which is coupled to the flange of the syringe barrel, and a shield which is telescopically mounted to the holder. Two hands are required to operate this system.
SUMMARY OF THE INVENTION
This invention relates to a safety shield system for a syringe, medical cartridge or the like and such a system as used in combination with an assembly capable of functioning as a syringe. In accordance with the preferred embodiment of the system, the user is able to cause the shielding of a needle cannula by simply applying additional pressure to the plunger rod of the syringe following injection of the contents of the syringe barrel. The shield may accordingly be deployed automatically through the use of only one hand. As there is no need to place the hand near the needle for any purpose, the risk of needle stick injury is further reduced.
In accordance with the objects of the invention, a medical device is provided which includes an automatically operable shield system mounted to a syringe barrel. The system includes a tubular holder which defines an enclosure. A tubular needle shield is slidably attached to the holder and preferably telescopically received within the holder. The syringe barrel is received within the holder and shield assembly, preferably within the tubular shield, and the shield is extendable from a retracted position, wherein the needle cannula is exposed to an extended position, wherein the shield encloses the needle cannula following injection. A compressed spring is located within the holder and shield assembly which biases the shield axially toward the extended position. The shield is releaseably retained to the holder, such that upon application of force to the stopper following injection, the shield is released from the retracted position and the spring drives the shield to the extended position. In the disclosed embodiment, the shield includes a stop member adjacent its proximal end and the holder includes a stop member adjacent its distal end which releaseably retains the shield in its retracted position. In the preferred embodiment, the stop member on the holder is an annular internal groove adjacent the distal end of the holder and the stop member on the shield is a radially outwardly extending annular rib. In the most preferred embodiment, the shield includes a further stop member in the form of a second radial rib adjacent the proximal end of the shield which engages the stop member on the holder when the shield is extended to its extended position. The force of the compressed spring by itself is insufficient to disengage the stop member adjacent the distal end of the shield and the stop member on the holder. However, axial movement of the syringe following injection, disengages the stop members and releases the shield. It is intended to cover the needle tip when in the extended position. The syringe barrel is operably coupled to the shield such that sufficient axial movement of the syringe barrel causes axial displacement of the shield sufficient to cause disengagement of the stop members. Such movement of the barrel is ordinarily caused by pressure on the plunger rod of the syringe, driving the stopper against the end of the barrel following complete injection of the contents of the barrel. Upon disengagement of the first and second stop members, the spring causes the shield to move to the extended position.
The proximal end of the holder is preferably adapted to engage and retain the syringe flange upon receipt of the syringe barrel through the proximal end of the holder. The axial or distal movement of the shield is preferably limited by a second abutment surface or rib adjacent the proximal end of the shield which engages a radially inwardly projecting distal end portion of the holder. Such movement could alternatively be limited by a tether connecting the holder and shield. The shield is preferably positioned within the holder such that the spring engages a stop member extending radially outwardly from the shield. The opposite end of the spring can bear against any suitable surface, operably connected to the holder, preferably a flange on the end fitting.
The shield system according to the invention is comprised of a holder, a shield, a spring and an end fitting which receives the spring and which isolates the syringe from the holder, reducing damage to the syringe flange. The tubular shield is adapted for receiving a syringe. The shield is slidably mounted to the holder, and is movable between a retracted position, wherein the shield needle cannula is exposed and an extended position wherein the needle cannula is enclosed. A spring urges the shield towards the extended position. The holder includes a stop member which is engageable with a first stop member of the shield to maintain it in the retracted position. Sufficient axial movement of the syringe barrel causes disengagement of the stop members, allowing the spring to move the shield to the extended position. The holder is engageable with a second portion of the shield axially-spaced from the first portion to prevent decoupling of the shield and holder when the shield moves to the extended position. An end fitting is incorporated in the system to maintain the position of the spring prior to insertion of a syringe into the holder, prevent direct contact of the spring and the syringe flange and isolate the syringe flange from the holder during extension of the shield, preventing damage to the syringe flange.
The tubular holder includes an inwardly opening annular channel or chamber adjacent the open proximal end which receives the flanges of the syringe and fitting. The chamber includes opposed first and second abutment surfaces to retain the flanges. The fitting is located within the holder and includes a
Gagnieux Samuel
Jansen Hubert
Becton Dickinson and Company
Fortunato David M.
Hayes Michael J.
Kontos Lina R
LandOfFree
Safety shield system for prefilled syringes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Safety shield system for prefilled syringes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Safety shield system for prefilled syringes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3205130